Method of preparing beta titanium-fiber reinforced composite laminates

ABSTRACT

A method of preparing a beta titanium-fiber reinforced composite laminate comprising the steps of, first, providing a beta titanium alloy having a first yield strength to modulus of elasticity ratio; then, heating the beta titanium alloy at a first preselected temperature for a first preselected time to produce a beta titanium alloy having a second yield strength to modulus of elasticity ratio; and then, adhering a fiber reinforced composite having a strength to modulus of elasticity ratio to the beta titanium alloy to produce a beta titanium-fiber reinforced composite laminate; wherein the first preselected temperature and the first preselected time are preselected such that the second yield strength to modulus of elasticity ratio of the beta titanium alloy is substantially similar to the strength to modulus of elasticity ratio of the fiber reinforced composite.

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a divisional of U.S. patent application Ser. No.08/588,868 filed Jan. 19, 1996, entitled BETA TITANIUM-REINFORCEDCOMPOSITE LAMINATES, now U.S. Pat. No. 5,578,384, issued Nov. 26, 1996,which is a continuation-in-part of U.S. patent application Ser. No.08/568,530 fled Dec. 7, 1995, entitled CARBON-TITANIUM COMPOSITES, whichis a continuation of U.S. patent application Seri. No. 08/139,091,entitled TITANIUM AND GRAPHITE FIBER COMPOSITES, filed Oct. 18, 1993,now abandoned, the contents of which are incorporated herein byreference in their entirety.

BACKGROUND

Many industrial applications require materials that possess acombination of high strength, low weight and damage resistance. In orderto meet these needs, both metals and metal-composite laminate materialsare utilized.

One application for materials possessing high strength, low weight anddamage resistance are for the construction of parts for motor and humanpowered vehicles in order to provide satisfactory structural integrityand damage resistance, while increasing the range of the vehicle for agiven amount of fuel or power. Such vehicles include automobiles,trucks, planes, trains, bicycles, motorcycles, and spacecraft. Otherapplications include golf clubs (both the shaft and the head), tubularstructures such as softball bats, skis, and surf and snow boards.

In order to meet the needs of the aerospace industry, for example, anumber of metal-composite laminate materials have been developed toreplace the metals traditionally used in the construction of aircraftprimary structures. The problems with these composite materials,however, include a mismatch between the strength to modulus ofelasticity ratio of the different layers. This mismatch causes variouslayers of the composite to fail under a specific amount of stress beforeother layers of the composite, thereby underutilizing the strength onthe non-failing layers. Thus, currently used low weight metal-compositelaminate materials do not use the maximum strength of various layers fora given strain of the metal-composite laminate material.

Hence, there is a need for high strength, lightweight materials for usein industrial applications, such as for parts of motor and human poweredvehicles, among other uses. Further, there is a need for lightweight,metal-composite laminate materials which utilize the strength of alllayers of the material to the fullest extent per given strain of themetal-composite laminate material.

SUMMARY

According to one aspect of the present invention, there is provided amethod of preparing a beta titanium-fiber reinforced composite laminatecomprising the steps of, first providing a beta titanium alloy having asurface with an area and having a first yield strength to modulus ofelasticity ratio. Then, the beta titanium alloy is heated at a firstpreselected temperature for a first preselected time to produce a betatitanium alloy having a second yield strength to modulus of elasticityratio. Next, a fiber reinforced composite layer having a strength tomodulus of elasticity ratio is adhered to the beta titanium alloy toproduce a beta titanium-fiber reinforced composite laminate. The firstpreselected temperature and the first preselected time are preselectedsuch that the second yield strength to modulus of elasticity ratio ofthe beta titanium alloy is substantially similar to the strength tomodulus of elasticity ratio of the fiber reinforced composite.

In a preferred embodiment, the method additionally comprises a step ofcoating the surface of the beta titanium alloy with a noble metal suchas platinum to produce a coated beta titanium alloy after the providingstep. In another preferred embodiment, the method additionally comprisesa step of abrading the surface of the beta titanium alloy to increasethe area of the surface after the providing step. In another preferredembodiment, the method additionally comprises a step of priming thesurface with a primer after the heating step. According to anotheraspect of the present invention, there is provided a beta titanium-fiberreinforced composite laminate produced according to the method.

According to still another aspect of the present invention, there isprovided a beta titanium-fiber reinforced composite laminate comprisinga first layer of beta titanium alloy having a surface and a first layerof fiber reinforced composite, wherein the first layer of beta titaniumalloy has a yield strength to modulus of elasticity ratio that issubstantially similar to the strength to modulus of elasticity ratio ofthe first layer of fiber reinforced composite. The surface of the betatitanium alloy can be coated with a noble metal such as platinum. Thebeta titanium-fiber reinforced composite laminate can also comprise aplurality of layers of beta titanium alloy, and, interspersedtherebetween, at least one layer of fiber reinforced composite, whereineach layer of beta titanium alloy has a yield strength to modulus ofelasticity ratio that is substantially similar to the strength tomodulus of elasticity ratio of the at least one layer of the fiberreinforced composite.

According to still another aspect of the present invention, there isprovided a method of making an article of manufacture comprising thesteps of, first preparing a beta titanium-fiber reinforced compositelaminate according to the present invention. Then, the betatitanium-fiber reinforced composite laminate is incorporated into thearticle of manufacture. Examples of such articles of manufacture includea motor vehicle, a golf club, a softball bat, a ski, a surf board, asnow board and a container.

According to still another aspect of the present invention, there isprovided a method of preparing a metal-fiber reinforced compositelaminate comprising the steps of, first, providing a metal having asurface with an area and having a first yield strength to modulus ofelasticity ratio. Then, the metal is heated at a first preselectedtemperature for a first preselected time to produce a metal having asecond yield strength to modulus of elasticity ratio. Next, a fiberreinforced composite having a strength to modulus of elasticity ratio isadhered to the metal to produce a metal-fiber reinforced compositelaminate. The first preselected temperature and the first preselectedtime are preselected such that the second yield strength to modulus ofelasticity ratio of the metal is substantially similar to the strengthto modulus of elasticity ratio of the fiber reinforced composite, andthe metal has a second yield strength to modulus of elasticity ratiothat is greater than about 1%.

BRIEF DESCRIPTION OF THE DRAWINGS

These features, aspects and advantages of the present invention willbecome better understood with regard to the following description andappended claims in the accompanying figures (not necessarily drawn toscale) where:

FIG. 1 is a side elevational view of a cross-section through a betatitanium-fiber reinforced composite laminate according to the presentinvention;

FIG. 2 is a side elevational view of a cross-section through a betatitanium-fiber reinforced composite laminate according to anotherembodiment of the present invention;

FIG. 3 is a side elevational view of a cross-section through a betatitanium-fiber reinforced composite laminate according to anotherembodiment of the present invention;

FIG. 4 is a side elevational view of a cross-section through a betatitanium-fiber reinforced composite laminate according to anotherembodiment of the present invention;

FIG. 5 is a flow diagram of one embodiment of the method according tothe present invention;

FIG. 6 is a side elevational view of a cross-section through a hatsection stiffener with beta titanium-fiber reinforced compositelaminates according to the present invention bonded to the flangesections; and

FIG. 7 is a side elevational view of a cross-section through a betatitanium-fiber reinforced composite laminate according to anotherembodiment of the present invention.

DESCRIPTION

As disclosed herein, the present invention includes, among otherembodiments, a beta titanium-fiber reinforced composite laminate, amethod for making a beta titanium-fiber reinforced composite laminate,and structures comprising a beta titanium-fiber reinforced compositelaminate. Beta titanium-fiber reinforced composite laminates accordingto the present invention and laminates made according to the presentinvention advantageously have high strength to weight ratios, excellentdamage resistance, tend to be highly fatigue resistant and corrosionresistant and have excellent shock dampening characteristics, amongother advantages as will be understood by those with skill in the artwith reference to the disclosure herein.

The beta titanium-fiber reinforced composite laminate of the presentinvention comprises at least a first layer of a beta titanium alloyhaving a surface. The layer of beta titanium alloy can be at least onebeta titanium alloy selected from the group consisting of TIMETAL® 15-3(Ti 15V-3Cr-3Al-3Sn), BETA 21s® (Ti 15Mo-3Al-3Nb), BETA C® (Ti3Al-8V-6Cr-4Zr-4Mo) and B120 VCA (Ti 13V-11Cr-3Al), though other betatitanium alloys can be used as will be understood by those with skill inthe art with reference to the disclosure herein. In a preferredembodiment, the beta titanium alloy is TIMETAL® 15-3 (Ti15V-3Cr-3Al-3Sn) (available from Titanium Metals Corporation, Toronto,Ohio).

The beta titanium-fiber reinforced composite laminate of the presentinvention further comprises at least one layer of a fiber reinforcedcomposite. The fiber reinforced composite can be at least one fiberreinforced composite selected from the group consisting of graphitereinforced epoxies (such as HERCULES® IM7/8551-7 available from HerculesAdvanced Materials and Systems Company, Magna, Utah), and S2-glassreinforced epoxies (such as 3M SP 381, available from 3M AerospaceMaterials Department, St. Paul, Minn.), though other fiber reinforcedcomposites can be used as will be understood by those with skill in theart with reference to the disclosure herein. In a preferred embodiment,the fiber reinforced composite is a graphite reinforced epoxy, FiberiteIM7/977-3 (epoxy prepreg tape) (available from Fiberite, Orange,Calif.).

The layer of beta titanium alloy is bonded to the layer of fiberreinforced composite, thereby producing a laminate structure. Accordingto the present invention, the beta titanium alloy layer of the laminatehas a yield strength to modulus of elasticity ratio that issubstantially similar to the strength to modulus of elasticity ratio ofthe layer of fiber reinforced composite. This substantial matching ofyield strength to modulus of elasticity ratio of the beta titanium alloylayer with the strength to modulus of elasticity ratio of the fiberreinforced composite layer produces a lightweight, strong anddamage-resistant material suitable for a wide range of uses.

As used herein, "substantially similar" refers to within about 40%(forty percent). In preferred embodiments of the present invention, theyield strength to modulus of elasticity ratio of the beta titanium alloylayer is within about 33% (thirty-three percent) of the strength tomodulus of elasticity ratio of the fiber reinforced composite layer. Ina particularly preferred embodiment, the yield strength to modulus ofelasticity ratio of the beta titanium alloy layer is within about 10%(ten percent) of the strength to modulus of elasticity ratio of thefiber reinforced composite layer. In a preferred embodiment, the designlimitations of the fiber reinforced composite layer have a limit loadthat is less than the maximum design load, thus giving a usable strengthto modulus ratio of about 1.2% that closely matches the yield strengthto modulus of elasticity ratio of the beta titanium alloy layer.

Referring now to FIG. 1, there can be seen a side elevational view of across-section through a beta titanium-fiber reinforced compositelaminate 10 according to the present invention, comprising a fiberreinforced composite layer 12 that is bonded directly to the surface 14of the beta titanium alloy layer 16.

Referring now to FIG. 2, there can be seen a side elevational view of across-section through a beta titanium-fiber reinforced compositelaminate 20 according to another embodiment of the present invention.While similar to the embodiment shown in FIG. 1, this preferredembodiment includes a layer of a noble metal 18 bonded to the surface 14of the beta titanium alloy layer 16, thereby creating a noble metallayer 18 between the surface 14 of the beta titanium alloy layer 16 andthe fiber reinforced composite layer 12. Suitable noble metals includeat least one metal selected from the group consisting of gold, silver,and palladium, though other noble metals can also be suitable as will beunderstood by those with skill in the art with reference to thedisclosure herein. In a particularly preferred embodiment, the noblemetal is platinum (available from Metal Surfaces, Bell Gardens, Calif.).

Referring now to FIG. 3, there can be seen a side elevational view of across-section through a beta titanium-fiber reinforced compositelaminate 30 according to another embodiment of the present invention. Inthis preferred embodiment, the beta titanium-fiber reinforced compositelaminate 30 comprises a plurality of layers of beta titanium alloy 16and, interspersed therebetween, at least one fiber reinforced compositelayer 12. The embodiment shown in FIG. 3 comprises two fiber reinforcedcomposite layers interspersed between three beta titanium alloy layers.Each beta titanium alloy layer 16 has a yield strength to modulus ofelasticity ratio that is substantially similar to the strength tomodulus of elasticity ratio of the at least one fiber reinforcedcomposite layer 12.

The beta titanium alloy layers 16 can be at least one beta titaniumalloy selected from the group consisting of TIMETAL® 15-3 (Ti15V-3Cr-3Al-3Sn), BETA 21s® (Ti 15Mo-3Al-3Nb), BETA C® (Ti3Al-8V-6Cr-4Zr-4Mo) and B120 VCA (Ti 13V-11Cr-3Al), though other betatitanium alloys can be used as will be understood by those with skill inthe art with reference to the disclosure herein. In a preferredembodiment, the beta titanium alloy is TIMETAL® 15-3 (Ti15V-3Cr-3Al-3Sn) (available from Titanium Metals Corporation, Toronto,Ohio). The plurality of layers of the beta titanium alloy 16 cancomprise the same beta titanium alloy or can comprise different betatitanium alloys. For example, one layer of the plurality of layers ofbeta titanium alloy can comprise BETA 21s® while another layer of theplurality of beta titanium alloy layers can comprise TIMETAL® 15-3.

The at least one layer of fiber reinforced composite 12 can be at leastone fiber reinforced composite selected from the group consisting ofgraphite reinforced epoxies (such as HERCULES® IM7/8551-7 available fromHercules Advanced Materials and Systems Company, Magna, Utah), andS2-glass reinforced epoxies (such as 3M SP 381, available from 3MAerospace Materials Department, St. Paul, Minn.), though other fiberreinforced composites can be used as will be understood by those withskill in the art with reference to the disclosure herein. In a preferredembodiment, the fiber reinforced composite is a graphite reinforcedepoxy, Fiberite IM7/977-3 (epoxy prepreg tape) (available from Fiberite,Orange, Calif.).

When more than one layer of fiber reinforced composite is present, theplurality of fiber reinforced composite layers 12 can comprise the samefiber reinforced composite or can comprise different fiber reinforcedcomposites. For example, one layer of the plurality of layers of fiberreinforced composite can comprise graphite reinforced epoxy whileanother layer of the plurality of fiber reinforced composite layers cancomprise S2-glass reinforced epoxy.

Referring now to FIG. 4, there can be seen a side elevational view of across-section through a beta titanium-fiber reinforced compositelaminate 40 according to another embodiment of the present invention.While similar to the embodiment shown in FIG. 3, this preferredembodiment includes a layer of a noble metal 18 bonded to each surface14 of each beta titanium alloy layer 16, thereby creating a noble metallayer 18 between each surface 14 of each beta titanium alloy layer 16and each fiber reinforced composite layer 12. Suitable noble metalsinclude at least one metal selected from the group consisting of gold,silver, and palladium, though other noble metals can also be suitable aswill be understood by those with skill in the art with reference to thedisclosure herein. In a particularly preferred embodiment, the noblemetal is platinum (available from Metal Surfaces, Bell Gardens, Calif.).

According to another aspect of the present invention, there is provideda method of preparing a beta titanium-fiber reinforced compositelaminate. FIG. 5 is a flow diagram of one embodiment of the methodaccording to the present invention.

The method 100 comprises the step 110 of first providing a beta titaniumalloy having a surface with an area and having a first yield strength tomodulus of elasticity ratio. Next, the method comprises the step 120 ofheating the beta titanium alloy at a first preselected temperature for afirst preselected time to produce a beta titanium alloy having a secondyield strength to modulus of elasticity ratio. Then, the methodcomprises the step 130 of adhering a fiber reinforced composite to thebeta titanium alloy to produce a beta titanium-fiber reinforcedcomposite laminate. The fiber reinforced composite has a strength tomodulus of elasticity ratio. The first preselected temperature and thefirst preselected time are preselected such that the second yieldstrength to modulus of elasticity ratio of the beta titanium alloy issubstantially similar to the strength to modulus of elasticity ratio ofthe fiber reinforced composite.

Suitable first preselected temperatures and suitable first preselectedtimes can be determined by those with skill in the art with reference tothe disclosure herein and will vary with the second yield strength tomodulus of elasticity ratio desired. In a preferred embodiment, thefirst preselected temperature is between about 450° C. and about 700°C., and the first preselected time is between about eight hours andabout sixteen hours. In a particularly preferred embodiment, the firstpreselected temperature is about 510° C., and the first preselected timeis about eight hours.

In another preferred embodiment, the method of preparing a betatitanium-fiber reinforced composite laminate additionally comprises thestep 112 of abrading the surface of the beta titanium alloy after theproviding step, thereby increasing the surface area to allow greaterbonding between the surface and a noble metal coating, or between thesurface and an adhesive coating.

In another preferred embodiment, the method of preparing the betatitanium-fiber reinforced composite laminate additionally comprises thestep 114 of coating the surface of the beta titanium alloy with a noblemetal to produce a coated beta titanium alloy after the providing step.The noble metal can be selected from a group consisting of gold, silver,and palladium, though other noble metals can also be suitable as will beunderstood by those with skill in the art with reference to thedisclosure herein. In a preferred embodiment, the noble metal isplatinum.

Further, in another preferred embodiment, the method additionallycomprises the step 122 of priming the surface with a primer afterheating the beta titanium alloy. The primer can be selected from anysuitable primer such as a low solid, high solvent epoxy glue, as will beunderstood by those with skill in the art with reference to thedisclosure herein. In a preferred embodiment, the primer is EC 3917(available from 3M Aerospace Materials Department, St. Paul, Minn.).

In a preferred embodiment, the adhering step 130 comprises applying anadhesive to the surface of the beta titanium alloy in order to bond thefiber reinforced composite layer to the beta titanium alloy layer.Suitable adhesives will be determined by the nature of the fiberreinforced composite. An example of a suitable adhesive is AF 191(available from 3M Aerospace Materials Department, St. Paul, Minn.).

The adhering step 130 can also comprise heating the beta titanium alloyand the fiber reinforced composite at a second preselected temperaturefor a second preselected time in order to cure the laminate. Suitablesecond preselected temperatures and suitable second preselected timescan be determined by those with skill in the art with reference to thedisclosure herein. In a preferred embodiment, the second preselectedtemperature is between about 150° C. and 200° C., and the secondpreselected time is between about 45 minutes and 90 minutes. In aparticularly preferred embodiment, the second preselected temperature isabout 180° C. and the second preselected time is about 70 minutes.

Pressure can also be applied as part of the curing process to assist increating the bond between the beta titanium alloy layer and the fiberreinforced composite layer. Suitable pressures can be determined bythose with skill in the art with reference to the disclosure herein. Ina preferred embodiment, the pressure is between about 30 and about 100psi.

Suitable beta titanium alloys and suitable fiber reinforced compositesfor use in the methods according to the present invention include thematerials disclosed herein for the beta titanium-fiber reinforcedcomposite laminates according to the present invention.

According to another embodiment of the present invention, there isprovided a method of making an article of manufacture or a part thereof.The method comprises preparing a beta titanium-fiber reinforcedcomposite laminate according to the methods disclosed herein andincorporating the beta titanium-fiber reinforced composite laminate intoan article of manufacture or part. Articles of manufacture or partsthereof suitable for preparation by this method include articles ofmanufacture in which lightweight, high strength materials are needed.Examples of parts of articles of manufacture include parts of motor andnon-motor vehicles (like automobiles, planes, trains, bicycles,motorcycles, and spacecraft), such as I-beams, C-channels, hat sectionstiffeners, plates, facings for honeycomb sandwich panels, and tubes.Other suitable articles of manufacture include golf clubs (both theshaft and the head), tubular structures such as softball bats, skis,surf and snow boards, and cargo containers.

The present invention further includes an article of manufacture, or apart thereof, which comprises a beta titanium-fiber reinforced compositelaminate according to the present invention or a beta titanium-fiberreinforced composite laminate prepared according to a method of thepresent invention. The article of manufacture or part thereof comprisesa beta titanium-fiber reinforced composite laminate having a first betatitanium alloy layer having a surface and a first fiber reinforcedcomposite layer, where the first beta titanium alloy layer has a yieldstrength to modulus of elasticity ratio which is substantially similarto the strength to modulus of elasticity ratio of the first fiberreinforced composite layer. The article of manufacture or part thereofcan further comprise a second beta titanium alloy layer such that thefirst fiber reinforced composite layer is between the first betatitanium alloy layer and the second beta titanium alloy layer. Thesecond beta titanium alloy layer has a yield strength to modulus ofelasticity ratio that is substantially similar to the strength tomodulus of elasticity ratio of the first fiber reinforced compositelayer. The surface of the first beta titanium alloy layer can be coatedwith a noble metal such that the noble metal is between the surface ofthe beta titanium alloy and the first fiber reinforced composite layer.In a preferred embodiment, the noble metal is platinum.

FIG. 6 is a side elevational view of a cross-section through a hatsection stiffener 70 as would be found in an aircraft with betatitanium-fiber reinforced composite laminates 72 according to thepresent invention bonded to the flange sections 74.

According to another aspect of the present invention, there is provideda method of preparing a metal-fiber reinforced composite laminate. Themethod comprises steps of first providing a metal having a surface withan area and having a first yield strength to modulus of elasticityratio. Next, the metal is heated at a first preselected temperature fora first preselected time to produce a metal having a second yieldstrength to modulus of elasticity ratio. Then, a fiber reinforcedcomposite having a strength to modulus of elasticity ratio is adhered tothe metal to produce a metal-fiber reinforced composite laminate. Thefirst preselected temperature and the first preselected time arepreselected such that the second yield strength to modulus of elasticityratio of the metal is substantially similar to the strength to modulusof elasticity ratio of the fiber reinforced composite. The metal has asecond yield strength to modulus of elasticity ratio that is greaterthan about 1.2%. In a preferred embodiment, the metal has a second yieldstrength to modulus of elasticity ratio that is greater than about 1.0%.

EXAMPLE 1 METHOD FOR PREPARING A BETA TITANIUM-FIBER REINFORCEDCOMPOSITE LAMINATE AND BETA TITANIUM-FIBER REINFORCED COMPOSITE LAMINATEPRODUCED ACCORDING TO THE METHOD

A beta titanium-fiber reinforced composite laminate according to thepresent invention was prepared by the method for preparing a betatitanium-fiber reinforced composite laminate according to the presentinvention as follows. First, a coil of 0.020 inch gauge TIMETAL® 15-3(Ti 15V-3Cr-3Al-3Sn) (available from Titanium Metals Corporation,Toronto, Ohio) beta titanium alloy was provided. These beta titaniumalloy sheets had a first yield strength to modulus of elasticity ratioof about 1.1%. Next, the coil was rolled to 0.010 inch gauge accordingto methods well known to those with skill in the art and cut intoindividual sheets of approximately 24 inches by 24 inches.

While not essential, at least one surface of each of the beta titaniumalloy sheets was sandblasted to increase the surface area according totechniques well known to those with skill in the art. Next, a layer ofplatinum was applied to the sandblasted surfaces of the sheets throughan electroless process according to techniques well known to those withskill in the art, creating platinum coated, beta titanium alloy sheets.

Then, the platinum coated, beta titanium alloy sheets were age-hardenedby heating at a preselected temperature of 510° C. for a preselectedtime of eight hours in a vacuum chamber. This heating resulted inhardened, platinum coated, beta titanium alloy sheets having a secondyield strength to modulus of elasticity ratio 1.2%. Besides changing theyield strength to modulus of elasticity ratio, the heating also causedthe removal of titanium oxide from the surfaces of the sheets, therebyimproving the adherence of the platinum to the surfaces.

While not essential, the hardened, platinum coated, beta titanium alloysheets were primed by spraying EC 3917 (available from 3M AerospaceMaterials Department, St. Paul, Minn.). The primed, hardened, platinumcoated, beta titanium alloy sheets were allowed to air dry for about onehour and then cured for a predetermined time of about one hour at apredetermined temperature of about 120° C.

Fiber reinforced composite layers were then added to the primed,hardened, platinum coated, beta titanium alloy sheets to create betatitanium-fiber reinforced composite laminates according to the presentinvention. Each fiber reinforced composite layer contained six plies ofIM7/977-3 (epoxy prepreg tape) (available from Fiberite, Orange, Calif.)having a thickness of approximately 0.0052 inches, for a total thicknessof approximately 0.031 inches per layer. All of the IM/977-3 wereapplied along the length or along the direction intended to carry mostof the load. Although not essential, a glue, AF 191 (available from 3MAerospace Materials Department, St. Paul), was utilized to secure theIM7/977-3 to the titanium sheets. The laminates were then cured in aflat press at 100 psi and 180° C. for one hour and cooled to roomtemperature while maintaining 100 psi pressure. The total thickness ofthe beta titanium-fiber reinforced composite laminate, including twolayers of beta titanium alloy, three layers of fiber reinforcedcomposite and adhesive was about 0.10 inches.

Referring now to FIG. 7, there is shown a side elevational view of across-section through the beta titanium-fiber reinforced compositelaminate 50 produced according to this Example. As can be seen, thelaminate 50 comprises three layers of beta titanium alloy 52, each layerhaving a platinum coating 54 thereon. Interspersed between the threelayers of beta titanium alloy 52 are two layers 56 of carbon fiberprepreg tape, IM7/977-3, each layer comprising six plies of carbon fiberprepreg tape. Between each platinum coating 54 on the beta titaniumalloy layers 52 and the IM7/977-3 layers 56 was a layer of EC 3917primer 58 and a layer of AF 191 adhesive 60, as shown.

Although the present invention has been described in considerable detailwith reference to certain preferred embodiments thereof, otherembodiments are possible. For example, beta titanium-fiber reinforcedcomposite laminates of the present invention can be utilized toconstruct sandwich panels which comprise beta titanium-fiber reinforcedcomposite laminates according to the present invention on either side ofa separating structure such as honeycomb (available from AdvancedHoneycomb, San Marcos, Calif.). Therefore, the spirit and scope of theappended claims should not be limited to the description of thepreferred embodiments contained herein.

I claim:
 1. A method of preparing a beta titanium-fiber reinforcedcomposite laminate comprising the steps of:(a) providing a beta titaniumalloy having a surface with an area and having a first yield strength tomodulus of elasticity ratio; (b) heating the beta titanium alloy at afirst temperature for a first time to produce a beta titanium alloyhaving a second yield strength to modulus of elasticity ratio; and (c)adhering a fiber reinforced composite having a strength to modulus ofelasticity ratio to the beta titanium alloy to produce a betatitanium-fiber reinforced composite laminate; wherein the firsttemperature and the first time are such that the second yield strengthto modulus of elasticity ratio of the beta titanium alloy issubstantially similar to the strength to modulus of elasticity ratio ofthe fiber reinforced composite.
 2. The method of claim 1, additionallycomprising a step of coating the surface of the beta titanium alloy witha noble metal to produce a coated beta titanium alloy after theproviding step (a).
 3. The method of claim 2, wherein the noble metal isplatinum.
 4. The method of claim 1, additionally comprising a step ofabrading the surface of the beta titanium alloy to increase the area ofthe surface after the providing step (a).
 5. The method of claim 1,additionally comprising a step of priming the surface with a primerafter the heating step (b).
 6. The method of claim 5, wherein the primeris a low solid, high solvent epoxy glue.
 7. The method of claim 1,wherein the adhering step (c) comprises applying an adhesive to thesurface of the beta titanium alloy.
 8. The method of claim 1, whereinthe adhering step (c) comprises heating the beta titanium alloy and thefiber reinforced composite at a second temperature for a second time. 9.The method of claim 1, wherein the beta titanium alloy provided in step(a) is selected from the group consisting of (Ti 15V-3Cr-3Al-3Sn), (Ti15Mo-3Al-3Nb), (Ti 3Al-8V-6Cr-4Zr-4Mo) and (Ti 13V-11Cr-3Al).
 10. Themethod of claim 1, wherein the fiber reinforced composite of step (c) isselected from the group consisting of graphite reinforced epoxies andS2-glass reinforced epoxies.
 11. The method of claim 1, wherein thefirst temperature of step (b) is approximately 510° C. and the firsttime of step (b) is approximately 8 hours.
 12. The method of claim 1,wherein the second yield strength to modulus of elasticity ratio of thebeta titanium alloy produced by step (b) is within about 40% of thestrength to modulus of elasticity ratio of the fiber reinforcedcomposite of step (c).
 13. The method of claim 1, wherein the secondyield strength to modulus of elasticity ratio of the beta titanium alloyproduced by step (b) is within about 10% of the strength to modulus ofelasticity ratio of the fiber reinforced composite of step (c).
 14. Amethod of making an article of manufacture, comprising the steps of:(i)preparing a beta titanium-fiber reinforced composite laminate accordingto the method of claim 1; and (ii) incorporating the beta titanium-fiberreinforced composite laminate into the article of manufacture.
 15. Themethod of making an article of manufacture of claim 14, wherein thearticle of manufacture of step (ii) is selected from the groupconsisting of a motor vehicle, a golf club, a softball bat, a ski, asurf board, a snow board and a container.
 16. The method of making anarticle of manufacture of claim 14, wherein the article of manufactureof step (ii) is a motor vehicle part.
 17. A method of preparing ametal-fiber reinforced composite laminate comprising the steps of:(a)providing a metal having a surface with an area and having a first yieldstrength to modulus of elasticity ratio; (b) heating the metal at afirst temperature for a first time to produce a metal having a secondyield strength to modulus of elasticity ratio; and (c) adhering a fiberreinforced composite having a strength to modulus of elasticity ratio tothe metal to produce a metal-fiber reinforced composite laminate;wherein the first temperature and the first time are such that thesecond yield strength to modulus of elasticity ratio of the metal issubstantially similar to the strength to modulus of elasticity ratio ofthe fiber reinforced composite; and wherein the metal has a second yieldstrength to modulus of elasticity ratio that is greater than about 1.2%.